Why Does My Car’s Heat Only Work While Moving?

QuestionsCategory: Ask An ExpertWhy Does My Car’s Heat Only Work While Moving?
Madison King asked 8 months ago
I have a 2008 Chevy Impala, and I'm facing an odd issue with the heating system. The heat only seems to work when the car is moving. If I turn on the heat while the car is idling in park, the blowers function but only emit cool air. The air starts warming up only once I drive around. I'm looking for some advice on what might be causing this and how to fix it.
1 Answers
Zack Norman Staff answered 8 months ago
Hi there, Madison! The AC issues that you're experiencing now are not uncommon, so the good news there is that fixes are readily available. Here's what you should check, based on your descriptions and explainers:
  1. Coolant Level: Start by checking the coolant level when the engine is cold. It should be at or slightly above the low mark on the overflow tank. If it's low, top it off and keep an eye out for any leaks.
  2. Radiator Hoses: Once the car is warm, feel the radiator hoses. They should be firm, not soft. If they're soft, consider replacing the coolant pressure cap.
  3. Thermostat and Car Temperature: Use a scanner to check the car's operating temperature. If it doesn't reach around 190°F or more, the thermostat might need replacing, assuming the coolant level and pressure cap are fine.
Other possible issues could include a clogged radiator or heater core, a worn-out water pump, or trapped air in the heater core, which may require "burping" the system to remove the air. If these checks don't resolve the issue, it might be worth considering a professional diagnostic. Do let me know how you get on! Zack - Motor Verso Mechanics Team